Question

如果事务中止，我想让NHibernate回滚事务期间保存的任何实体的标识符。我正在使用NHibernate 2.1.0，默认情况下它不会这样做。我想出了以下解决方案，它可以解决问题：

public class RevertIdentifiersEventListener : DefaultSaveEventListener
{
    private class RevertIdentiferSynchronization : ISynchronization
    {
        private IClassMetadata _classMetadata;
        private object _entity;
        private object _originalIdentifier;

        public RevertIdentiferSynchronization(IClassMetadata classMetadata, object entity)
        {
            _classMetadata = classMetadata;
            _entity = entity;
            _originalIdentifier = classMetadata.GetIdentifier(entity, NHibernate.EntityMode.Poco);
        }

        #region ISynchronization Members

        public void AfterCompletion(bool success)
        {
            if (success == false)
            {
                _classMetadata.SetIdentifier(_entity, _originalIdentifier, NHibernate.EntityMode.Poco);
            }
        }

        public void BeforeCompletion()
        {
        }

        #endregion
    }


    protected override object EntityIsTransient(SaveOrUpdateEvent @event)
    {
        IEntityPersister entityPersister = @event.Session.GetEntityPersister(@event.EntityName, @event.Entity);
        if (entityPersister.HasIdentifierProperty)
        {
            RevertIdentiferSynchronization revertIdentiferSynchronization = new RevertIdentiferSynchronization(entityPersister.ClassMetadata, @event.Entity);
            if (@event.Session.Transaction.IsActive)
            {
                @event.Session.Transaction.RegisterSynchronization(revertIdentiferSynchronization);
            }
        }
        return base.EntityIsTransient(@event);
    }

}

问题在于，如果实体的保存将保存级联到关联实体，则不会回滚该实体的标识符。上面的EntityIsTransient不会为这些实体调用，只会调用显式调用Save的那些实体。

关于如何在级联时使其工作的任何建议？

Answer 1

我不确定你想在什么情况下中止交易，但我假设你需要这样的事情：

    using( var transaction = SessionFactory.GetSession().BeginTransaction())
    {
        try
        {
           session.Update(entity); // throws exception for some reason
        }
        catch(Exception ex)
        {
            transaction.Rollback(); // rollback the transaction
        }
    }

回滚标识符NHibernate

1 个答案: